A reliable and accurate detection of the occurrence of a current strength of interest within signals is an important task in many applications. For example, the always increasing requirements in the area of power electronics lead to higher switching frequencies and more complex topologies. If it can be guaranteed that a power switch can be switched only at the zero crossing of a current, a possibility of constructing extremely efficient voltage converters can be provided. A necessary temporal sample rate of a few nanoseconds resulting from a corresponding resolution of the signal shape is caused by the switching frequencies getting in the region of megahertz. In other words, the zero current crossing (zero current detection, ZCS) in modern, high efficient, switched electric voltage converter should be measured accurate and very fast.